Fuse foot having bracket including interconnected relatively large and small loop portions



March 22. 1966 w. B. TAYLOR FUSE FOOT HAVING BRACKET INCLUDING INTERCONNECTED RELATIVELY LARGE AND SMALL LOOP PORTIONS 3 Sheets-Sheet 1 Filed March 13, 1965 INVENTOR William B. Tylor BY W 7 7ORIV y 5 March 22. 1966 w. B. TAYLOR 3,242,288

FUSE FOOT HAVING BRACKET INCLUDING INTERCONNECTED RELATIVELY LARGE AND SMALL LOOP PORTIONS Filed March 15, 1963 3 SheetsSheet 2 IN VENTOR.

William .BTa ylor March 22. 1966 w TAYLOR 3,242,288

FUSE FOOT HAVING BRACKETINCLUDING INTERCONNECTED RELATIVELY LARGE AND SMALL LOOP PORTIONS Filed March 15, 1963 3 Sheets-Sheet 5 i i i l 3 l l l I: INVENTOR fg g g l William BJZgyZar V20 BY United States Patent FUSE FOOT HAVING BRACKET INCLUDING IN- TERCONNECTED RELATIVELY LARGE AND SMALL LOOP PORTIONS William B. Taylor, 311 E. Elm Creek Drive, Longview, Tex. Filed Mar. 13, 1963, Ser. No. 264,904 11 Claims. (Cl. 200-114) This invention relates generally to electrical fuse mounting devices, and more particularly to an improved fuse support for use with fuse mountings of the type utilized with electrical power transmission line equipment.

Power transmission lines are commonly provided with cutout fuses, which typically include an elongated insulator element having fuse elements supports at its upper and lower ends, the latter commonly being denoted as a fuse foot and including a base secured to the insulator and a bracket detachably mounted on said base. A fuse element is clamped to said bracket, the upper end thereof being secured in position to the upper support by a suitable latch device. The opposite ends of the fuse element are connected to a transmission line so that electricity passes therethrough.

Commonly, cutout fuses are positioned at the top of utility poles or in other awkward positions, and a very large voltage is often present. These two factors combine to make the manipulation of the fuse foot to insert and remove fuse elements a difiicult, and often dangerous,.task. When a fuse element is blown it must be replaced, and to accomplish this an operator must manipulate the fuse foot to remove the old fuse and insert a new one. The combined difliculties of high voltage and inaccessibility demand that this replacement operation be as easy and as safe as possible.

Numerous foot constructions have been proposed for fuse mounting devices, and many have found widespread use. However, the need still exists for a fuse foot which can be easily and safely manipulated. The present invention is directed to a novel fuse foot which permits ready installation and removal of a fuse element with a minimum of danger to the Worker.

The fuse foot of the invention is constructed of two parts, a base secured to the lower end of an insulator element and a bracket attached to the lower end of the fuse. The bracket is easily attachable to and removable from the base to permit mounting of the fuse element thereon, and when in position on said base is secured for proper manipulative movement along a predetermined path.

- It is an object of this invention to provide an improved fuse mounting constructed for easy insertion and removal of a fuse element.

Another object of the present invention is to provide a foot for a fuse mounting device, said foot incorporating wide tolerances to facilitate easy assembly and disassembly thereof.

' It is also an object of this invention to provide a fuse foot for a fuse mounting which is constrained when assembled in operative position to move along a predetermined manipulative path.

A further object of the present invention is to provide a foot for a fuse mounting which is economical to construct, and which incorporates readily interchangeable elements.

An even further object of the invention is to provide a locking device for securing the bracket portion of a fuse mounting foot in position upon its base.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the following drawings.

FIG. 1 is a side elevational view of the fuse mounting foot of the invention;

FIG. 2 is an enlarged fragmentary vertical section of the base of the foot, taken along the line 2-2 in FIG. 1;

FIG. 3 is a section of the base of the foot, taken along the line 33 in FIG. 2, showing the manner in which the bracket is positioned thereon;

FIG. 4 is an enlarged fragmentary horizontal sectional view taken along the line 44 in FIG. 1, showing the bottom of the bracket;

FIG. 5 is an enlarged fragmentary view showing the manner in which the fuse bracket is mounted on the base, the initial position for mounting the bracket being shown in phantom lines;

FIG. 6 is a view similar to FIG. 5, but showing the bracket in its nearly installed position;

FIG. 7 is a fragmentary side elevation, partly in section, of a second embodiment of the base of the invent1on;

FIG. 8 is an enlarged fragmentary vertical section taken on the line 88 in FIG. 7.

FIG. 9 is an enlarged side elevation of a modified fuse bracket for use with the base of FIG. 8; and

FIG. 10 is a bottom view of the base bracket of FIG. 9.

The fuse mounting foot of the present invention is mounted on the lower end of an elongated insulator element, and comprises a base secured to said element and a bracket detachably secured to said base and having means thereon for holding a fuse. The base includes a supporting plate having a mounting shaft projecting normally therefrom and which terminates at its outer end in a stop plate. The bracket comprises a relatively large closed loop having the general shape of a parrallelogram, a smaller loop being positioned at one corner of said larger loop and in communication therewith.

The fuse element is secured by a pivotal mounting clamp to the side of said larger loop opposite said smaller loop, and the bracket is mounted on the base by first passing the larger loop over the stop plate and then manipulating it until the shaft enters the smaller loop. The base has means thereon which insures that the bracket will remain properly positioned once the smaller loop is engaged on the shaft, and which constrains the bracket to pivotal movement along a predetermined path.

The base has mounted thereon a resilient contact which engages a contact on the fuse bracket when the latter is in its closed position, said contacts automatically separating when the bracket is swung about the shaft from said closed position. The bracket is manipulated by an elongated insulated tool, whereby the workman is protected from electric current flowing therein, and the pivoted fuse mounting clamp incorporates a leaf spring which functions to swing the fuse element out of position when the latter is blown to thus facilitate removal thereof.

Referring now to the drawings, a fuse mounting device is indicated generally at 2 in FIG. 1, and includes an elongated insulator 4 having a clamping band 6 extending thereabout for use in mounting said insulator in position on a power transmission pole or other structure 7. A fuse foot, indicated generally at 8, is attached to the lower end of said insulator and comprises a base 10 having a flat mounting plate 12 thereon. The plate 1'2 has a bore therethrough through which .a screw 14 extends, said screw being threaded into the lower end of the insulator 4 and functioning to secure the base 10 in position. Obviously, if desired the base 10 might be secured to the insulator by means other than that illustrated.

The base 10 also includes a supporting plate 16 dis- Patented Mar. 22, 1966 posed at .a right angle to the mounting plate 12 and extending a substantial distance forwardly from the in sulator 4 and from the forward edge of said mounting plate. A mounting shaft 18 is secured centrally of said supporting plate and projects normally therefrom, said shaft terminating in a stop plate 20. The lower portion of the stop plate 20 is generally semicircular, and a rounded positioning tab 22 extends outwardly at an angle from the top edge 24 thereof. As is evident from. FIGS. 1 and 2, the top edge 24 of the stop plate extends a substantial distance above the shaft 18, the purpose of this being described hereinbelow.

Mounted upon the shaft 18 of the foot base is a bracket 26, said bracket including a relatively large loop 28 comprised of front and back legs 30 and 32 interconnected by top and bottom legs 34 and 36, respectively. The legs of the large loop are arranged to generally define a parallelogram, and a second, relatively small, loop 38 extends substantially normally form the back leg 32 at the juncture of said leg with the bottom leg 36. The loop 3 8 is defined by top and bottom legs interconnected by a. semicircular portion 40, and is in communication with the space defined by the large loop. The spacing between the legs of the smaller loop corresponds to the diameter of the shaft 18 which is received therein, and the thickness of both the loops is substantially uniform through out.

The widths of both of the loops are also uniform throughout except for a narrower portion 42 on the bottom leg 36 of the larger loop. The uniform width of said loops corresponds, to the spacing between the supporting plate 16 and the stop plate 20, and said two plates have tabs, or protrusions, '43 and 44 thereon which engage the rounded portion of the smaller loop 38 when the latter is positioned on the shaft 18, and which function to confine said smaller loop so that it is in engagement with said shaft throughout a pivotal movementv range of well over 90 degrees.

' The manner in which the bracket 26 is mounted on the base 10 is illustrated in FIGS. 5 and 6. Initially, the bracket is held in the orientation indicated by phantom lines in FIG. 5, with the narrow portion 42 of the larger loop 28 positioned above the shaft 18. The large loop is then passed over the stop plate 20, the opening defined by the legs thereof being substantially larger than the stop plate to provide adequate clearance for this manipulation; the tab 22 functions as a guide to facilitate movement of the-bracket into position, When the bracket has, been moved directly over the shaft 18, it is moved vertically downward so that the reduced width portion 42 passes between the protrusions 43 and 44, and. rests on the shaft 18, as shown in solid lines in FIG. 5. The bracket is then rotated to the position shown in FIG. 6, with the shaft 18' entering the smaller loop 38. When the bracket has moved sufficiently so that the protrusions 43 and 44 are no longer above the reduced width portion 42, the bracket will be securely held on the shaft 18 by said protrusions. It is thus seen that the bracket may be easily installed because of the wideg-clearances available, but that once it is in position on the shaft it will be closely constrained to follow a predetermined pivotal path. The bracket 26 has a transverse bore therethrough at the juncture of the legs 30 and 34, and a bifurcated portion of a. clamp 46 is received over said juncture and is pinned thereto by a pivot pin 48. A conventional fuse element 50 is received within the clamp 46, and the bottom lead 52 there-of passes through an opening 53 in the leg 36-and is secured to the inside of the leg 30 by a wing nut binding post arrangement 54; the exterior of the leg 30 in the vicinity of the binding post has an increased thickness portion 56 thereon against which the lower end of the fuse element 50 rests. A leaf spring 58 is secured to the exterior of the leg 30 in the vicinity of the pivot pivot away from the increased thickness portion, or pad, 56. A teat 60 on the rear top edge of the clamp 46 is arranged so that it may engage leg 34 and thus limit the degree to which the upper end of the fuse element may pivot toward the insulator 4.

The top of the fuse element 50 has mounted thereon. a portion 62 of a latch arrangement 64. The other portion of the latch is an elongated resilient member 63 mounted on the upper end of the insulator 4, and when the two halves of the latch are engaged, as shown, the fuse element 50 is held rigidly in position. The latch 64 may be of any of the conventional types well known to the art, and hence will not be described in detail herein; it provides an electrical path between the top contact of the fuse element 50 and a binding post 66 on top of the insulator 4. The latch 64 is frictionally engaged, and may be readily sprung open by pulling on the ring 68 provided on the latch portion 62.

The mounting plate 12 has a resilient, leaf spring con doctor 70 attached to-the forward edge thereof and which. terminates in a contact head 72. The back leg 32 of the bracket 28 has an upswept contact arm 74 extending. therefrom in posit-ion to engage the contact head 72 when the fuse element 50 is in its. installed position. with the. latch 64 engaged. The mating contact surfaces 7 2 and 74 provide a conductive path to the fuse lead 52, the. bracket 28 being constructedof a conductive material. This contact arrangement is known in the prior art, and hence will not be further described herein.

The upwardly swept contact arm 74 also serves two other important functions inthe present invention. First, the upper end thereof cooperates with the contact 72 to limit rearward tilting of the bracket 28. More importantly, however, the arm 74 provides. a means for engaging the bracket 28 with a transverse shaft 76 on an installing tool 78, shown in FIG. 5.. The installing tool 78 is of a type known to the art, andcornprises a pole 80 surmounted by an L-shaped hook arrangement 82, said two elements being separated by insulation 84. Thus,,the bracket 28 may be handled safely without danger of electrical shock to the worker.

In use, the insulator 4 is. mounted in position on a suitable structure by the use of the band 6. Electrical leads are secured to the binding post 66 and. to a binding post 86 on the mounting plate 12. Fuse element 50 is mounted on the bracket 28 andsaidbracket is installed on the base 10. in themanner illustrated in FIGS. 2 and 5 by the use of the tool 78. The fuse element is then swung counterclockwise about shaft 18 until the latch 64 is engaged, and current is then conducted between the two terminals 66 and 86 through the fuse element 50. It is seen that the novel fuse foot8, because of the wide clearances and constraining features incorporated therein, facilitates easy and safe installation of the fuse element;

The fuse foot embodiment of FIG. 1 provides a device which satisfies each of the objects set forth for the invention. A second embodimentof the invention is shown. in;

FIGS. 7 to 10,. which embodiment is substantially more stable inpivoting action than that of .FIG. 1, and which incorporates means to retain the bracket in. itsclosed: position.

Referring to said FIGS. 7' to 10, a base 88 having a mounting plate90 thereon is shown attached to an insulator 92 by aband clamp 94,.said base including a support; plate 96 having a protrusion 98 thereon. A shaft 100) projects normally from the plate 96 and terminates in a: stop plate 101 having a similar protrusion 102 thereon, the: protrusion 98 being positioned a substantial distance far-- ther from the shaft 100 than the protrusion 102. The shaft 100 has a fiat portion 1'04thereon for a purpose to be hereinafter described.

A bracket 106 is shown in FIGS. 8 and 9, and'is sub-- stantially identical to the bracket 26 except in-the con-v struction of the smaller loop 108 thereof; A flat Washer 110 is attached asby welding to the upper leg: of the small loop 108 in the region 112, only, and is cut away in the area defined between the legs on said loop; the bracket has a recess 114 therein of a depth to receive said Washer. The closed end 116 of the loop has a slit 118 therein, whereby the two legs thereof are separated from each other.

The bracket 106 is installed on the shaft 100 in the same manner as described hereinabove with respect to the embodiment of FIG. 1, the protrusions 98 and 102 riding upon the circular periphery of the washer 110 and the loop 108, respectively, when said shaft is received within said loop 108. The washer 110 insures that the bracket Will be laterally stabilized through a relatively wide pivotal arc.

The purpose for the flat portion 104 on the shaft 100 and the split 118 in the loop 108 is to provide a resilient cam action for restraining the bracket in its closed position. The slit 118 divides the arms defining the loop 108- into two resilient arms, this resiliency being insured by having the washer 110 secured only to one of said arms. The flat portion 104 is positioned so that the bracket portion defining the upper side of small loop 108 will lie thereover when said bracket is swung downwardly into its open position. The thickness of the shaft 104, measured normally through said flat portion is about the same as the distance between the arms defining the small loop. When the bracket is swung closed the arms defining the loop 108 will engage the rounded portions of the shaft 104, and the resilient characteristics of said arms will cause them to frictionally engage said shaft in a cam action to thereby tend to hold the bracket against rotation. The specific location and configuration for the fiat portion of the shaft is largely a matter of choice. The washer 110 has a notch 120 therein which permits the bracket some movement on the shaft 100 against the resiliency of the lower arm defining the loop 108.

Obviously, many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. In a fuse support, a fuse foot comprising: a base; a support plate on said base and having a shaft projecting therefrom; a bracket including interconnected relatively large and relatively small loop portions, said small loop portion being receivable on said shaft for pivotal motion t-hereabout; and means for retaining said relatively small loop portion of said bracket on said shaft, comprising: a stop plate secured to the end of said shaft remote from said support plate; and a projection on at least one of said stop plate and said support plate spaced radially from said shaft in position to engage the outer periphery of said relatively small loop portion of said bracket.

2. A fuse foot as recited in claim 1, wherein said relatively small loop portion of said bracket is of a substantially uniform Width throughout corresponding to the distance between said support plate and said stop plate, and wherein said relatively large loop portion of said bracket adjacent said relatively small loop portion does not exceed in width the width of the latter and includes a portion having a width less than the distance measured between the closest positions on said projection and the plate opposite thereto.

3. In a fuse support, a fuse foot comprising: a base, said base including a support plate; a shaft projecting normally from said support plate and terminating in a stop plate, said stop plate including a portion disposed parallel to said support plate; a bracket including interconnected relatively large and relatively small loop portions, said relatively large loop portion being receivable over said stop plate, and said relatively small loop portion terminating in a closed arcuate end of a diameter slightly greater than that of said shaft and being receivable thereon; and projection means on at least one of said plates positioned to extend toward the other thereof and to engage the outer periphery of said closed arcuate end.

4. A fuse foot as recited in claim 3, wherein said relatively small loop portion has a uniform width throughout of slightly less than the distance between said plates, and wherein said relatively large loop portion adjacent said relatively small loop portion does not exceed in Width the width of the latter and includes a portion having a width less than the distance measured between said projection and said opposite plate.

5. A fuse foot as recited in claim 4, wherein said stop plate additionally includes an outwardly projecting, inclined tab for facilitating the mounting of said bracket thereon.

6. A fuse foot as recited in claim 4, including additionally: a resilient electrical contact mounted on said base; and a contact arm on said bracket positioned to engage said resilient contact when said bracket is pivoted theretoward.

7. A fuse foot as recited in claim 6, including additionally: a fuse; a clamp holding said fuse and pivotally attached to said relatively large loop portion of said bracket remote from said relatively small portion; and resilient means disposed between said bracket and said fuse for urging said fuse to pivot away from said bracket.

8. A fuse foot as recited in claim 7, including additionally a projection on said clamp positioned to engage said bracket for limiting the pivotal movement of said fuse.

9. A fuse foot as recited in claim 4, wherein said arcuate end of said relatively small loop has a discontinuity thereon, whereby said relatively small loop is defined by a pair of resilient arms, and wherein said shaft has a non-uniform cross section, the normal spacing between said resilient arms corresponding to the minimum cross sectonal measurement of said shaft.

10. A fuse foot as recited in claim 9, including additionally; a washer secured to one of said arms to lie in the plane of said bracket and disposed concentrically about said arcuate portion, said washer being cut away between said arms; and a projection on one of said plates positioned to engage the periphery of said washer.

11. A fuse foot as recited in claim 10, wherein said washer has a cutout therein disposed diametrically opposite the point of attachment of said washer to said arm, said cutout lying under said other arm and being of a size to receive said shaft.

References Cited by the Examiner UNITED STATES PATENTS 2,074,094 3/1937 Rush 248-293 2,359,153 9/1944 Rawlins 200114 2,681,963 6/1954 Fahnoe 200114 ROBERT K. SCHAEFER, Acting Primary Examiner, BERNARD A. GILHEANY, Examiner. 

3. IN A FUSE SUPPORT, A FUSE FOOT COMPRISING: A BASE, SAID BASE INCLUDING A SUPPORT PLATE; A SHAFT PROJECTING NORMALLY FROM SAID SUPPORT PLATE AND TERMINATING IN A STOP PLATE, SAID STOP PLATE INCLUDING A PORTION DISPOSED PARALLEL TO SAID SUPPORT PLATE; A BRACKET INCLUDING INTERCONNECTED RELATIVELY LARGE AND RELATIVELY SMALL LOOP PORTIONS, SAID RELATIVELY LARGE LOOP PORTION BEING RECEIVABLE OVER SAID STOP PLATE, AND SAID RELATIVELY SMALL LOOP PORTION TERMINATING IN A CLOSED ARCUATE END OF A DIAMETER SLIGHTLY GREATER THAN THAT OF SAID SHAFT AND BEING RECEIVABLE THEREON; AND PROJECTION MEANS ON AT LEAST ONE OF SAID PLATES POSITIONED TO EXTEND TOWARD THE OTHER THEREOF AND TO ENGAGE THE OUTER PERIPHERY OF SAID CLOSED ARCUATE END. 